Sphincter of Oddi Dysfunction.

Sphincter of Oddi dysfunction (SOD) is a benign noncalculous obstruction of bile or pancreatic drainage at the level of the sphincter of Oddi. The disorder is clinically associated with either biliary pain or idiopathic pancreatitis, depending on the portion of the sphincter affected. Patients with suspected SOD are subdivided into three categories: these are type I, II, and III, depending on associated clinical evidence for the diagnosis. Multiple noninvasive tests have been utilized to aid in the diagnosis but have been complicated by poor sensitivity and specificity. Sphincter of Oddi manometry is the gold standard for confirming the diagnosis, although questions remain about its sensitivity and specificity. Sphincterotomy of the affected portion of the sphincter is the treatment of choice and has been shown effective for palliation of symptoms in two sham-controlled studies of patients with suspected type II biliary SOD.